London: Theresa May bowed out as UK Prime Minister on Wednesday with a farewell speech at Downing Street before tendering her resignation to Queen Elizabeth II.
She wished new Prime Minister Boris Johnson and his government well, saying: "Their successes will be our country's successes."
May said that Johnson's immediate priority will be to "complete our exit from the European Union in a way that works for the whole United Kingdom".
She said that Brexit could start a "new beginning for our country, a national renewal that can move us beyond the current impasse".
Her speech was interrupted by a campaigner who shouted "stop Brexit" to which May replied "I think the answer to that is I think not".
May received a standing ovation from Conservative MPs when she left the House of Commons chamber after her final Prime Minister's Questions (PMQs).
During her PMQs, she said that she would continue as a constituency MP and was "looking forward to asking the questions" in future.
Labour leader Jeremy Corbyn acknowledged May's "respect for public service", but criticized her record on the economy, homelessness and Brexit. He asked whether she would consider joining him "in opposing the reckless plans of her successor".
She, in reply, listed what she felt were her successes, including school improvements, more employment and greater home ownership.
After May formally tenders her resignation to the Queen at Buckingham Palace, Johnson will visit the monarch and will be invited to form a government before addressing the nation and is expected to start announcing his Cabinet Ministers.
The former Foreign Secretary, who was widely expected to win the leadership race, beat his rival, current Foreign Secretary Jeremy Hunt, by a margin of 92,153 votes to 46,656.
In his victory speech, he said he had three priorities taking office: to "deliver, unite and defeat".
He added that the slogan made the acronym "dud" until you added the final element, "energize," which, in fact, made it "dude".
The former London Mayor has been a vocal critic of May's withdrawal agreement with the European Union, deeming it over-conciliatory, and has vowed that the UK will leave on 31 October "do or die".
Michel Barnier, the EU's chief Brexit negotiator, said they will be ready if Johnson pursues a no-deal strategy but it would never be the bloc's choice.
He told the BBC on Wednesday: "We look forward to hearing what the new prime minister Boris Johnson wants, what are the choices of the UK.
"Is it an orderly Brexit? This is the choice, the preference of the EU and we have worked for an orderly Brexit all along the last three years.
"Is it a no-deal Brexit? A no-deal Brexit will never be, never, the choice of the EU. But we are prepared."
Johnson's victory as Tory leader has resulted in a number of resignations from within the party.
Phillip Hammond resigned as Chancellor of the Exchequer on Wednesday. David Lidington, Cabinet Office minister, also announced his resignation on Twitter.
On Tuesday, Development Secretary and former leadership contender Rory Stewart, Justice Secretary David Gauke and Skills Minister Anne Milton all resigned.
Alan Duncan, Foreign Minister, a less senior posting than a Secretary of State in the UK, resigned on Monday.